This invention relates to static seals, of the kind comprising a jacket of soft gasket material, and a filling or packing material within the envelope.
The invention is applicable particularly but not exclusively to seals intended for sealing surfaces which are not perfectly flat or not perfectly parallel, for example flange and body connections of glass-lined or enamel pressure vessels. In such vessels, the surface coating of glass, enamel or other protective material inevitably introduces a lack of flatness, both axially and circumferentially. Distortion of the flange surfaces occurs when the glass powder that has been sprayed onto the vessel surfaces is fused, the fusing temperature being in the region of 750.degree. C. A seal for sealing such surfaces must be capable of accommodating the lack of flatness.